Design, Fabrication, and Testing of a New Compact Piezo-Driven Flexure Stage for Vertical Micro/Nanopositioning

Abstract

This paper presents the design of a new compact one-degree-of-freedom (1-DOF) compliant stage driven by a piezoelectric actuator (PEA) for micro/nanopositioning in the vertical direction. An orthogonal compound bridge-type amplifier is introduced to amplify the displacement of the PEA. It significantly reduces the height of the stage and leads to a compact design. By analytical modeling of the mechanism, the design variables are determined, which are then optimized via the multiobjective genetic algorithm based on the finite-element analysis. Simulation results show that the 1-DOF stage is able to provide the maximum displacement of $181.18~\mu \text{m}$ in theory, which is more than $12\times $ the input displacement of PEA. Payload test results indicate that the stage can support a maximum load of about 80 N. Comparison study reveals that the presented vertical positioning stage offers a more compact structure than existing ones. A prototype is fabricated for experimental studies, and the deviation between the experimental and simulation results is discussed in detail. Moreover, closed-loop performance test exhibits a resolution of 10 nm for the developed vertical positioning stage. Note to Practitioners —The motivation of this paper is to devise a compact flexure-based stage, which can be mounted on the top of an XY stage for constructing a hybrid type of XYZ stage dedicated to micro/nanopositioning applications. Such a design scheme provides a more flexible solution than serial- and parallel-kinematic designs. In order to fulfill the design requirement and to improve the compactness and output directionality of the stage, a series of design processes is conducted. The design parameters are optimized and the optimal design leads to the stage dimension of 58 mm $\times20$ mm $\times15.5$ mm (length $\times $ width $\times $ height), which offers a motion range of $97.32~\mu \text{m}$ as verified by the experimental study. In consideration of the motion range and physical size, the proposed stage offers a more compact structure than available designs. Experimental results demonstrate the fine performance of the developed prototype stage for vertical micro/nanopositioning.